Escape boom

ABSTRACT

An escape device and method is provided for use with offshore rigs as a means for men to get off of the rig, while at the same time ending up at some distance from the rig, and providing a collecting point for the men. The structure includes a boom, a head attached to the boom, the boom being pivotally connected to the rig, with lifelines extending between the rig and the head, all of which is biased to extend the boom to the in service position, which places the head some distance from the rig.

United States Patent n91 Fitzgerald, deceased et al.

[451 Apr. 29, 1975 ESCAPE BOOM [75] Inventors: Hugh Joseph Fitzgerald, deceased,

late of Austin, Tex., by Marva Jean Fitzgerald, administratrix; Edward James Kwadas, New Orleans, La.

[73] Assignee: Resolution Engineering and Development Company, Houston, Tex.

[22] Filed: Dec. 27, 1972 [21] Appl. No.: 318,917

[30] Foreign Application Priority Data Dec. 30. I971 United Kingdom 60688/71 [52} US. Cl. 182/2; l82/l0; 182/82; 182/97 [51] Int. Cl A62b 1/00 [58] Field of Search 182/2, 10, II, 191, 192, l82/l93, 141, 82, 97

vvvwlt W [56} References Cited UNITED STATES PATENTS 772.094 l0/l904 Fosselman l82/98 3,731,761 5/[973 Glenn l82/l Primary ExaminerReinaldo P. Machado Attorney. Agent, or FirmPaul L. DeVerter, ll

[57] ABSTRACT 10 Claims, 11 Drawing Figures PATENTEU APR 2 9 I975 SHEET 1. BF 5 ESCAPE BOOM BACKGROUND OF THE INVENTION This invention concerns an escape device. and more particularly an escape boom which is particularly useful as a means to provide apparatus. and a method. which men may utilize to get off ofa burning or otherwise hazardous offshore platform.

The current practice when a fire starts on a drilling platform or production platform is simply to get off of the rig in the least amount of time. For this purpose. stringers or short masts are provided which have knot ted lines hanging downwardly from them. upon which the men may climb to descend. Also. balsa or other light liferafts with retaining lines (tag lines) are provided. In addition. inflatable liferafts are often provided. Nearly all rigs provide ladders or steps to the water. Most of these prior devices require the men to descend vertically t'o the water. before they can attempt to escape from the immediate proximity of the rig. Unfortunately. when rigs are on fire. the fire rarely burns directly vertically. but instead. the pressure of the gas or oil. hitting obstructions. throws the fire in many directions.

SUMMARY The present invention contemplates a boom which is pivotally attached to the platform. and which upon release will pivot to a generally horizontal position. Running from the rig platform. to the extended end of the boom. are a number of lifelines. which are for utilization by the men on the rig to slide down in the event of fire. The extended end of the boom may include a head member. which provides a platform for the men to collect on while awaiting rescue by boats. The boom is biased in such a manner that the natural forces of buoyancy or gravity will pivot the boom outwardly from the rig. when released.

It is a primary object of this invention to provide a method and means for a person to get off ofa rig. while at the same time providing a method and means to get some distance away from the rig and into or above the water. and to provide something to hang onto once the person has gotten off of and away from the rig.

Other and further objects. features and advantages will be apparent from the following description of the presently preferred embodiments of the invention. given for the purpose of disclosure. when taken in conjunction with the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Like character references designate like parts throughout the several views of the drawings. which are:

FIG. I is a general representation of an offshore platform showing the boom of the present invention on the left in a standby position. and on the right in an in service position.

FIG. 2 is a side view of one embodiment of the invention. showing the escape boom in a standby position.

FIG. 3 is a front view. partially in section. of the boom shown in FIG. 2.

FIG. 4 is a partial side view. showing one form of head attached to a boom.

FIG. 5 is a side view of a variant type of boom. similar to that shown in FIG. 2.

FIG. 6 is a front view of the variant boom shown in FIG. 5.

FIG. 7 is a partial side view. showing the boom of FIG. 5 when in an in service position.

FIG. 8 is a side view of the second embodiment of the invention. wherein the boom is pivotally attached to the platform at the deck.

FIG. 9 is a side view ofa third embodiment of the invention. showing this embodiment in both standby. and in service positions.

FIG. 10 is an enlarged partial side view of the third embodiment. shown in FIG. 9, when in an in service position.

FIG. II is a partial side view showing a boom of the first embodiment and a method of controlling the re trieving line.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings. and particularly to FIG. 1. the reference numeral It) generally designates the escape boom of the present invention. which is shown mounted on a rig I2 in the water [4. The rig [2 may be a production platform. or a drilling platform. both for use in an offshore environment. and may be fixed to the ocean bed. or may be of the floating variety. The deck 16 of the rig 12 is substantially above the mean level of the water 14. so that it is unaffected by waves. even during storm conditions. Mounted on the deck may be appropriate drilling structures [8. living quarters 20. and store rooms 22. The escape boom 10. shown on the left portion of FIG. 1 is in the standby position. such that the boom 24 is substantially vertical. The boom 24 is attached to the legs 26 and the rig I2 by a pivotal connection 28. The opposite end of the boom 24 is connected to a head 30. which may be likewise pivotally connected. Extending from the head 30 to appropriate standards 32 on the rig 12 are one or more lifelines 34.

As seen in the righthand portion of FIG. 1. when the escape boom 10 is in its in service position. the boom 24 is pivoted outwardly so that the head is extended from the rig. as opposed to the standby position. In this instance. the boom 24 has pivoted about the pivotal connection 28 with reference to the leg 26. The boom 24 is below the surface of the water I4. but the head 30 rises above the water. The various lifelines 34 are depicted in their deployed position thereby providing a method for a man. otherwise trapped on the rig I2. to get off of the rig. and onto the head 30. which is now some distance from the rig [2.

Although forming no part of the present invention. the men may slide. or climb. or use various mechanical devices for traveling down the lifelines 34 to the head 30. Note that the lifelines may be attached to the rig 12 at a variety of locations and elevations.

Referring now to FIGS. 2 and 3. a more complete explanation of the first embodiment of the invention will be given. The boom 24 is pivotally attached. by the pivotal connection 28 to the legs 26 of the rig l2. This pivotal connection is well below the surface of the water 14. and the boom 24 extends upwardly to the deck 16. of the rig l2. Mounted on the declt I6 is an appropriate winch 36. upon which is wound a retrieving line 38 which connects to the head 30 mounted on the boom 24. Also mounted on the deck 16 is a storm latch 40. which is simply a device to prevent sideways movement of the boom 24. because of wave action. when it is in a vertical. or standby position. Also mounted on the deck 16 are standards 32. Lifelines 34 are connected from the head 30 to the standards 32 and thence to lifeline spools 42. mounted on the deck I6. The connection of the lifelines 34 to the head 30 may be by way of stanchions 44. which are perhaps better seen in FIGS. 4 and 7.

The head 30 is buoyant. and is here shown connected to the boom 24 by the simple pivotal connection 46. Referring particularly to FIG. 3. it will be noted that the pivotal connection 28. which is beneath the water 14 simply comprises a T-shaped member 48. through which passes a shaft 50. Each end of the shaft 50 is appropriately secured to legs 26 of the rig 16 by means of the clamp assembly 52. Extending from each clamp assembly to the boom 24. adjacent the head 30 may be wire rope stays 54 whose function are to prevent wave forces from destroying the escape boom 10.

Referring again to FIG. 2. it will be noted that the boom 24. when in its standby position. is not truly vertical. but is instead offset from the vertical by an angle 56. which is sufficient to cause gravity to launch the escape boom 10. even during a storm. This angle causes an unbalanced horizontal component of force large enough to cause natural launching of the boom. To prevent such launching. the winch 36 and retrieving line 38 are utilized. To place the escape boom I in the in service position. many alternatives may be utilized. The simplest is. of course. to simply part or release the retrieving line 38. This might be done remotely by an explosi\ e charge. or by pulling a pin. or by a fuseable link. or by releasing the brake on the winch 36. When in launched position. the escape boom is shown as 10' in FIG. 2.

Referring again to FIG. 3.. it will he noted in the cutaway portion thereof. that the boom 24 contains a number of compartments or tanks. Below the surface of the water 14 may be one or more set tanks 58, while above the water may be one or more trim or tuning tanks 60. The function of the compartmented boom 24 is to provide a controlled deceleration of the boom as it is launched. and also to provide for final position of the boom when in its in service position. It is desired that the boom 24 have an overall negative buoyancy (i.e. will sink but both the set tanks 58 and trim tanks 60 may be adjusted to control the amount of negativeness. as well as controlling the time or speed of descent of the boom. and the ultimate altitude or angle of the boom when in its in launch (10') position. For this purpose. the set tanks 58 will have no controls. but may be arranged to be either positive or negative in buoyancy. The trim tanks 60 may contain ballast. such as water.

lead. mud. air. polyurethane. or the like. and. being generally above the surface of the water 14. may be adjusted. without the use of divers.

While the boom 24 has a negative buoyance. the head will have a positive buoyancy. ample in quantity to support both the boom 24 and also to provide free board when in its in service position. such as is indicated in FIGS. 4 and 7. Referring to these figures. it will be noted that the head 30 must also support men who reach it by means of the lifelines. and may also be compartmented to contain emergency provisions and supplies. As seen in FIG. 4. the head 30 maybe directly connected to the boom 24 by means of the pivotal connection 46. It may also be separated from the boom 24 by an articulated arm 62. as seen in FIG. 7. which is in turn pivotally connected to the boom 24 and head 30 by means of the pivotal connections 64 and 66. at either end thereof. When the articulated arm 62 is utilized. it will be noted that the boom 24 may be further below the surface of the water 14. thereby allowing more unrestricted access to that portion of the head 30 which is adjacent the rig 12. Note also that in FIGS. 4 and 7 the retrieving line 38 is shown connected from the head 30, and more particularly from the stanchions 44 upwardly to the deck of the rig. This retrieving line configuration. when utilized. may be used for pulling the boom upwardly to the standby position. and may also be used with an appropriate winch 36 to prevent sinking of the head 30 should its buoyant compartment become damaged. if the winch is provided with a maximum payout device. In all of the various booms shown. it is contemplated that when in the service position. the head will be at least 50 feet away from the rig l2. and in most instances. the distance will be 100 feet or greater.

Referring now to FIGS. 5 and 6. a variant of the first embodiment of the invention is shown. with the boom taking the shape of an A-frame device. Here the boom 68 is pivotally connected by means ofa pivotal connections 70 to the clamp assemblies 52. which are in turn attached to appropriate legs 26 of the rig I2. At the upper end. the head 30 is shown attached to the boom 68 by means of the articulated arm 62. previously described with reference to FIG. 7. Again. the various set tanks 58 and trim tanks 60 may be utilized in the A- frame boom 68. The remaining portions. which have been given numbers corresponding to similar parts on FIGS. 2 and 3. will require no further description.

Referring now to FIG. 8. a second embodiment of the present invention is shown. In this instance. the escape boom is again pivotally connected to the rig. but this time at the top. and buoyant forces are utilized to lift the boom from its substantially vertical standby position to the in service position shown in dotted lines. More particularly. the escape boom I0 is attached to the rig 12 by means of the pivotal connection 72 on the deck I6 of the rig. Extending from this pivotal connection 72 is the boom 74 which terminates in the head 76, attached therto by the pivotal connection 78. Mounted on the deck 16 is an appropriate winch which mechanically connects to the boom 74 by means of the retrieving line 82. Appropriate pulleys 84 are utilized to control the retrieving line 82, and a storm collar 86 may be attached to the leg 26 of the rig to prevent wave action from damaging the boom 74.

As in the first embodiment. the boom 74 is offset from the vertical by an angle 88 which is sufficient to cause the horizontal component of force to launch the escape boom 10 to the position shown in dotted lines. as 10'. The natural force used for such launching. in this embodiment is buoyancy. and again compartments or tanks are utilized within the boom 74. Thus. the boom may include set tanks 90. as well as trim tanks 92. The trim tanks are above the water. and may be ballasted. or deballasted in conjunction with the set tanks 90 to provide a boom 74 which is slightly positive.

In addition to the various lifelines 34 as shown in the preceding embodiment. this embodiment may also include steps 94 along with a guide rail 96 to enable men to remove themselves from the deck I6 by walking down the boom 74. In other particulars. the various features shown with the first embodiment are applicable to this second embodiment. including the use of the articulated arm 62. and various means for launching the escape boom by means of fuseable links. and the like.

Referring now to FIG. 9, the third embodiment of the present invention is shown. in this embodiment. the escape boom 10 is pivotally connected to the rig at its upper end. and when a standby position is essentially horizontal. The natural force of gravity is utilized to lower the escape boom so that the head floats in the water. when in service. More particulaly. the escape boom 10 is mounted on the rig I2 above the water 14 adjacent the deck 16. A boom 98 is pivotally connected. by means of the pivotal connection 100 to the rig 12. To the opposite end of the boom is attached an appropriate head 102. which may also include an articulated arm I04. if desired. Attached to and extending from the opposite end of the boom 98 is a counterweight arm 106. to which is fixed the counterweight I08. The pivotal connection ")0 is arranged to allow the boom 98 not only to pivot downwardly, so that the head [02 is in the water 14, but also may be arranged to allow the boom 98 to swivel or swing outwardly. so that the head 102 is not simply below the deck 16. but is distant therefrom as well.

Referring now to FIG. 10. one means for providing such a pivotal connection 100 is shown. Here. it will be noted that a trunion ll0 interconnects the boom 98 and the rotating plate 112. The rotation of the rotating plate H2 is controlled by the cam "4 on the column 116. which is in turn attached to the deck 16. Through the medium of cam followers 118. both the angular displacement and rotation of the boom 98 are controlled, and the counterweight I08 is adjusted so that the boom is negatively biased. such that it will assume the in service position shown in FIG. 10. when released. Instead of the cam follower arrangement depicted. the swiveling and rotating action may be provided with a vertical slot and a simple inclined plane. or by independent rotating and pivoting motions. The boom 98 also contains steps 120 as well as a guide rail 122. and may include the lifelines 34 previously depicted with the other embodiments of the invention. it might also be noted. particularly with reference to this third embodiment. that in offshore locations wherein ice is present. it is not necessary that the head 102 actually float in the water. but instead it may be suspended above the surface.

It should be recognized in all instances. that the head may include davits to which an appropriate lifeboat. or floats. or similar devices may be attached. Referring now to FIG. ll, it should also be noted that a nonbuoyant head 124 may be provided at the end ofa simple boom 126, if the particular location of the escape boom 10 does not require such survival equipment. The retrieving line 38 is here shown going to a winch I28. which is in turn controlled by the hydraulic snubber I30, or other appropriate device. to allow the boom I26 to descend to the in service position, while regulating the speed of descent. and perhaps the ultimate service angle. Note that the lifeline 34 is attached to the head 124 and to the takeup spool 42 through the standard 32. The position of the lifeline 34 and retrieving line 38 are shown in dashed lines when the boom 126 is in the in service position.

Thus. it is seen that the present invention provides both apparatus and a method or new use for apparatus which would allow a man on a rig to remove himself from. while at the same time getting to a distant point. and providing an assembly point or head to hang onto once he has removed himself from the rig. in each in- 5 stance. an offsetting and unbalanced natural force is utilized to move the escape boom from its standby position to its in service position. and in each instance a method of controlling the speed and ultimate angle of displacement of the escape boom is provided. whether 10 by snubbers. cams. buoyancy. or the like.

The present invention. therefore, is well adapted to carry out the objects and attain the ends and advantages mentioned. as well as others inherent therein. While the presently preferred embodiments of the invention have been given for the purpose of disclosure. numerous changes in the details of construction. and the combination, shape. size. and arrangement of parts and uses may be resorted to without the parting from the spirit and scope of the invention.

What is claimed is: l. A method for providing means for escaping from an offshore. water surrounded. structure including:

pivotally mounting a boom on the structure at one end thereof. mounting a head on the other end of the boom. arranging the boom in an unbalanced position adjacent the structure. utilizing the unbalance to pivot the boom away from the structure when the boom is released. and extending at least one lifeline from the structure to the head when the boom is pivoted away from the structure. 2. A method for providing means for escaping from an offshore. water surrounded. structure including:

pivotally mounting a boom on the structure at one end thereof. mounting a head on the other end of the boom. arranging the boom in an unbalanced position adjacent the structure. utilizing the unbalance to pivot the boom away from the structure when the boom is released. controlling the speed of pivoting of the boom away from the structure, and utilizing the force of gravity as an unbalancing force. 3. An escape boom for use in providing a means for men to get off of and away from the deck of an offshore. water surrounded. structure as well as a collection point for the men. including:

an elongate boom. a head mounted on one end of the boom. a pivotal connection at the other end of the boom. pivotally connecting the boom to the structure. the boom. when in a standby position being adjacent the structure. and when in an in service position being pivotally extended from the structure. the boom. when in the standby position being biased to pivot to the in service position. retaining means releasably securing the boom in the standby position. and at least one lifeline extending from the structure to the head when the boom is in the in service position. 4. The invention of claim 3 including: the head buoyantly floating in the water when the boom is in the in service position. 5. The invention of claim 4 including:

an articulated arm pivotally interconnecting the head and the boom.

6. The invention of claim 4 including:

at least one stanchion extending upwardly from the head when the boom is in the in service position.

the lifeline being attached to the stanchion.

means maintaining the lifeline above the surface of the water when the boom is in the in service position.

7. The invention of claim 4 including:

compartments arranged in the boom. and

means for adjusting the buoyancy of the compartments.

8. The invention of claim 7 including:

the pivotal connection between the boom and the structure being below the surface of the water and the boom being adjusted for negative buoyancy.

otal connection. 

1. A method for providing means for escaping from an offshore, water surrounded, structure including: pivotally mounting a boom on the structure at one end thereof, mounting a head on the other end of the boom, arranging the boom in an unbalanced position adjacent the structure, utilizing the unbalance to pivot the boom away from the structure when the boom is released, and extending at least one lifeline from the structure to the head when the boom is pivoted away from the structure.
 2. A method for providing means for escaping from an offshore, water surrounded, structure including: pivotally mounting a boom on the structure at one end thereof, mounting a head on the other end of the boom, arranging the boom in an unbalanced position adjacent the structure, utilizing the unbalance to pivot the boom away from the structure when the boom is released, controlling the speed of pivoting of the boom away from the structure, and utilizing the force of gravity as an unbalancing force.
 3. An escape boom for use in providing a means for men to get off of and away from the deck of an offshore, water surrounded, structure as well as a collection point for the men, including: an elongate boom, a head mounted on one end of the boom, a pivotal connection at the other end of the boom, pivotally connecting the boom to the structure, the boom, when in a standby position being adjacent the structure, and when in an in service position being pivotally extended from the structure, the boom, when in the standby position being biased to pivot to the in service position, retaining means releasably securing the boom in the standby position, and at least one lifeline extending from the structure to the head when the boom is in the in service position.
 4. The invention of claim 3 including: the head buoyantly floating in the water when the boom is in the in service position.
 5. The invention of claim 4 including: an articulated arm pivotally interconnecting the head and the boom.
 6. The invention of claim 4 including: at least one stanchion extending upwardly from the head when the boom is in the in service position, the lifeline being attached to the stanchion, means maintaining the lifeline above the surface of the water when the boom is in the in service position.
 7. The invention of claim 4 including: compartments arranged in the boom; and means for adjusting the buoyancy of the compartments.
 8. The invention of claim 7 including: the pivotal connection between the boom and the structure being below the surface of the water, and the boom being adjusted for negative buoyancy.
 9. The invention of claim 7 including: the pivotal connection between the boom and the structure being adjacent the deck of the structure, and the boom being adjusted for positive buoyancy.
 10. The invention of claim 4 including: a swiveling connection in conjunction with the pivotal connection, the pivotal connection being adjacent the deck of the structure, the boom being generally horizontal when in standby position, and pivoting downwardly and swiveling outwardly to the in service position, and a counterweight extending from the boom in the direction opposite from the head and beyond the pivotal connection. 